The present invention relates to a precursor mixture of flavorings and flavoring components and to their use in the manufacture of food compositions.
It is known that sulfur-containing compounds are important constituents used to flavor foods. Indeed, it is disclosed, in the xe2x80x9cBACIS, VFC96, database of volatile compounds in food, 1996xe2x80x9d that thiol groups are present in food flavorings, and give off a roasted odor or a grilled odor when cooked. For example, the roasted odor or grilled odor is formed during the cooking of a variety of food compositions such as, meats, eggs, or vegetables; during the process of beer-making; and the roasting of coffee.
Unfortunately, thiols are unstable compounds which are often lost by evaporation or by oxidation. Hofmann et al. in J. Agric Food Chem., 1996, 44, 251-255 showed that thiols are oxidized to the corresponding disulfides after storage at a temperature of 60xc2x0 C.
Mottram et al., in J. Agric Food Chem., 1996, 44, 2349-2351, maintain that thiol groups can be formed by the reaction, in a hot aqueous solution, of disulfide compounds with proteins having sulfhydryl groups, in particular cysteines, or disulfide bridges, in particular cystines. In particular Mottram et al. reveals that heating an aqueous solution containing a disulfide and albumin leads to the release of thiol groups in a yield of 44.8%. That article, however, is entirely theoretical and does not mention either the possibility of starting with natural products or the formation of a complex. Furthermore, there is no application to the manufacture of flavorings.
U.S. Pat. No. 3,706,577, FR 1,423,176, EP 571,031, FR 2,222,030 and FR 2,205,280 relate to processes for manufacturing ready-to-use flavorings. In these patents, the aim is to manufacture an overall flavoring, i.e., a non-specific flavoring.
Thus, there remains a need for flavorings which specifically promote the release of a grilled odor or of a roasted odor during the cooking or heating of food compositions, and the present invention resolves this need.
The present invention relates to a precursor mixture of flavorings that includes at least one polysulfide and at least one non-volatile source of sulfur having at least one sulfhydryl group. The precursor mixture generates an aromatic note when it is heated due to the formation of thiols. The polysulfide is present in an amount sufficient to generate a thiol when heated to provide a roasted or grilled aromatic note. The non-volatile source of sulfur includes at least one sulfhydryl group and is present in an amount sufficient to react with the polysulfide to form the thiol and release of the aromatic note when the precursor mixture is heated.
The polysulfide can have the general formula Rxe2x80x94(S)nxe2x80x94Rxe2x80x2 wherein R and Rxe2x80x2 are identical or different and represent hydrogen; straight chain, branched chain or cyclic hydrocarbon groups, which may also include, unsaturation, heteroatoms and/or other functional groups; and aromatic groups, which may include heteroatoms, and which may be substituted or unsubstituted on the aromatic ring; and wherein n is greater than or equal to 2. The polysulfide may be obtained by bioconversion of a cysteine-aldehyde conjugate using a baker""s yeast.
The non-volatile source of sulfur, which may or may not be combined with other constituents, is selected from the group consisting of sulfur-containing amino acids, peptides containing at least one sulfur-containing amino acid, proteins containing at least one sulfur-containing amino acid, and protein hydrolysates containing at least one sulfur-containing amino acid.
In one embodiment the thiol is formed in a yield of 48-90%, when heated at neutral pH. In another embodiment the non-volatile source of sulfur is selected to be one or more proteins comprising at least one sulfur-containing amino acid and a hydrophobic pocket which forms a complex with the one or more polysulfides. This precursor mixture made of the complex can be dried so as to obtain a stable powder.
The invention also relates to a food composition that includes a food and a precursor mixture of flavorings. The precursor mixture of flavorings generates a roasted or grilled aromatic note when the food composition is heated. The precursor mixture of flavorings is preferably added in a proportion of about 0.07-0.50% by weight relative to the dry weight of the food composition.